An epidemiologic, cytogenetic, and pathologic study is being carried out to examine the relation of spontaneous abortion and fetal anomalies to use of alcohol, aspirin, heroin, methadone, marijuana and tranquilizers. Substances which are associated with spontaneous abortion will be identified through a comparison of exposure histories among women with spontaneous abortions (cases) and among women who deliver after 28 weeks gestation (controls). The mechanisms underlying the associations between specific substances and spontaneous abortions will be elucidated through a comparison of the karyotypic and morphologic characteristics of the conceptions of exposed and unexposed parents. Further understanding of fetal pathogenesis will be obtained through examination of selected characteristics of the live births from the control series in relation to exposure.